T helper 17 (Th17) cells are pathogenic in many inflammatory diseases, but also support the integrity of the intestinal barrier in a non-inflammatory manner. It is unclear what distinguishes inflammatory Th17 cells elicited by pathogens and tissue-resident homeostatic Th17 cells elicited by commensals. Here, we compared the characteristics of Th17 cells differentiating in response to commensal bacteria (SFB) to those differentiating in response to a pathogen (Citrobacter rodentium). Homeostatic Th17 cells exhibited little plasticity towards expression of inflammatory cytokines, were characterized by a metabolism typical of quiescent or memory T cells, and did not participate in inflammatory processes. In contrast, infection-induced Th17 cells showed extensive plasticity towards pro-inflammatory cytokines, disseminated widely into the periphery, and engaged aerobic glycolysis in addition to oxidative phosphorylation typical for inflammatory effector cells. These findings will help ensure that future therapies directed against inflammatory Th17 cells do not inadvertently damage the resident gut population.

中文翻译：

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肠道含有功能不同的稳态组织驻留细胞和炎症 Th17 细胞。

T 辅助 17 (Th17) 细胞在许多炎症性疾病中具有致病性，但也以非炎症方式支持肠道屏障的完整性。目前尚不清楚病原体引起的炎症性 Th17 细胞和共生体引起的组织内稳态 Th17 细胞的区别。在这里，我们比较了响应共生细菌 (SFB) 分化的 Th17 细胞与响应病原体 (Citrobacter rodentium) 分化的特征。稳态 Th17 细胞对炎性细胞因子的表达几乎没有表现出可塑性，其特征在于静止或记忆 T 细胞的典型代谢，并且不参与炎症过程。相比之下，感染诱导的 Th17 细胞对促炎细胞因子表现出广泛的可塑性，广泛扩散到外周，除了炎症效应细胞典型的氧化磷酸化外，还进行有氧糖酵解。这些发现将有助于确保未来针对炎症性 Th17 细胞的疗法不会无意中损害居民肠道菌群。